


Secret Relationship

by LilacChocolate



Series: Rin & Nitori [16]
Category: Free!
Genre: Boys Kissing, Fluff, Kissing, M/M
Language: English
Status: Completed
Published: 2017-04-25
Updated: 2017-04-25
Packaged: 2018-10-23 23:23:02
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,803
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10729416
Author URL: https://archiveofourown.org/users/LilacChocolate/pseuds/LilacChocolate
Summary: Rin and Ai are keeping their relationship a secret, but what will Rin do when another boy flirts with his boyfriend?





	Secret Relationship

For the third time that day, Rin was forced to watch the scene unfold in front of him. Ai was stood by the starting blocks, timing members of the swim team, and a second year, by the name of Jun, was flirting with him. He’d done it in the canteen at lunch, and now twice at swim practice. But Rin couldn’t do anything. He may have been going out with Ai, but they had agreed to keep the relationship a secret for the time being. Rin felt insecure, so he wanted to keep things between them just for now. He wanted to prove to Ai that he was worthy of him, before he had to prove it to everyone else. As soon as Gou, Seijuro, and the Iwatobi swim team found out, they would both be subjected to hours of questioning and Rin didn’t want there to be any doubt in Ai’s mind about Rin’s feelings for him.

And even now, despite how annoyed and scared Rin felt watching Ai flirt with someone else, he let it happen. He knew Ai wasn’t doing it intentionally. He and Rin had been flirting for months, and when Rin finally asked him out, the poor boy had no idea that’s what they had been doing. He probably thought Jun was just being friendly. Which, he technically was, but that didn’t mean Rin wasn’t jealous watching his cute boyfriend flirt with someone else.

By the time swim practice was over, Rin was seething. Jun had decided to do some actual swimming after flirting with Ai for about an hour, but in the locker rooms afterwards, he’d the audacity to look Ai up and down as he got changed. Luckily, Rin had noticed quickly, so when Ai took off his jammers, Rin made sure to stand directly behind him and block Jun’s view. Rin could just about handle another man flirting with his boyfriend, but he could not deal with another man seeing his boyfriend naked. Rin knew his fear was irrational: they were on a swim team. All of the boys had seen each other naked on far more than one occasion. But it was intentional stares directed at Ai that made Rin feel jealous and insecure. Ai was cute and kind and clever. He could have any boy on the swim team if he wanted them, even if they were straight.

On the way back to the dorm, Rin kept quiet, trying to hold in his anger and jealousy. Ai walked beside him, rambling away about how his day was and how much homework he had to do and oh, my gosh, senpai, I still haven’t watched the Shingeki no Kyojin episode from Saturday. Ai looked up at Rin. He wasn’t usually this unresponsive. He would usually offer to help with his homework, or hold him if the titans got too scary, or just let Ai know how his day had been. But there was nothing, not even a grunt of acknowledgment. Had Ai done something wrong? Was this the end of their relationship? They had only been together for a month; Ai wasn’t ready for it to end. He hadn’t told Rin yet, but Ai was in love with him. He had been since the day they met. It couldn’t end. They had to stay together.

They arrived back at their dorm, and when both boys had changed out of their school uniforms and into sweat pants and t-shirts, Rin finally spoke.

‘Who was that boy you were talking to?’

‘Which boy?’ Ai asked. The whole swim team was male. He needed a little more clarification.

‘The one who was flirting with you.’

‘No one was… Oh…’ Ai’s shoulders drooped. That’s why Rin had been so quiet. ‘It was Hara-senpai. I think he’s in your science class. I’m sorry, Rin-senpai.’ Ai bowed his head. ‘I didn’t realise that was flirting. I’ll apologise to Hara-senpai tomorrow, in case he thought I had feelings for him.’

‘Good.’

Ai looked up and frowned when he was Rin was still wearing a sour expression. ‘How would you like me to make it up to you, senpai?’

Rin stared at his boyfriend with raised eyebrows for a moment. _He really shouldn’t have asked that._ Rin placed both of his hands on Ai’s shoulders, then pushed him against the wall.

Ai looked up at Rin with wide eyes. What was he going to do to him? Before he could ask his boyfriend, Rin leant down and kissed Ai. The pressure of his senpai’s lips felt a little harder than usual, but their kiss was still as sweet as it had always been.

Rin’s hands made their way down Ai’s body and eventually settled on his hips. He thought about how Ai would look in his jammers with little fingerprint-shaped bruises on his hips, and how Jun would see them. The thought of the other boy got to Rin and he kissed harder, muffling a moan from Ai with his mouth.

The younger boy grabbed Rin’s arms as he kissed back. Every time they kissed, Ai felt weak at the knees. He knew it was cliché but he couldn’t help but melt against Rin’s body every time their lips touched.

Rin smiled against Ai’s mouth, but then he pulled away. Ai whined and went onto his tiptoes, wanting to kiss Rin again, but the redhead pushed Ai back against the wall.

Ai looked up, eyes narrowed now. ‘Senpai?’

‘That boy, Jun… I never want to see you talking to him again, okay?’

‘But-’

Ai was interrupted when Rin’s lips latched onto his neck and started to suck. The grey-haired boy gasped in shock, but he didn’t push his boyfriend away. They had never gone further than kissing, hugging, and holding hands, but he didn’t mind this. It felt nice with Rin’s lips against his neck, kissing and sucking. The redhead’s teeth grazed along his neck and Ai whimpered. His hands found their way into Rin’s hair and pulled and the second year sucked harder, enjoying the feeling of his boyfriend’s fingers in his hair.

Once he was satisfied with the mark he had surely made, Rin pulled away from Ai, then grabbed his wrist and took him over to the mirror that hung on the back of the door.

Ai gasped when he saw himself. His cheeks were flushed and his lips were swollen from the force of the kiss, but that wasn’t worrying him. On his neck was a red mark that Rin had kissed and sucked and bitten onto his skin. It was low enough that his school shirt would hide it, but there was no way he would be able to hide it at swim practice. ‘Senpai…’

Rin smirked from behind him. ‘Tomorrow, at practice, Jun shouldn’t come anywhere near you.’

Ai nodded, not sure what to say. He touched the mark with a tentative finger. It didn’t particularly hurt, but it was Rin’s mark. The small boy smiled and Rin walked over to the desk and picked up his phone.

‘I’ll order pizza.’

…

Later, after they’d both eaten, Rin and Ai were sat at the desks, doing homework. Ai was easily distracted by the mark on his neck, and to Rin, it seemed like he was touching it after he wrote every other sentence.

After twenty minutes, Rin had had enough of the guilt that was eating away at him and he put down his pen. ‘About before… I’m sorry. Did I hurt you?’

Ai looked up and shook his head with a smile. ‘No. Don’t be sorry. It was my fault. I should have known he was flirting with me. I’ll try to notice it more.’

‘But I shouldn’t have reacted like that.’ Rin looked away from his boyfriend. The redhead understood himself very well, and he knew that he lost his temper quickly. If Jun had done more than flirt, then Rin could have ended up seriously hurting Ai.

Ai got up and perched on the edge of his boyfriend’s desk. ‘Don’t worry. I kind of liked it, senpai.’

Rin looked up, surprised for a moment, and then smirked. ‘Everyone thinks you’re so innocent, but you’re actually just a cute little masochist, aren’t you?’

‘Senpai!’

…

The next day at swim practice, Rin stepped onto the pool deck with a smug smile on his face. Ai’s neck and chest was littered with marks and Jun would have to be an idiot to try and flirt with Ai when it was quite clear he was already taken.

‘Oi, Matsuoka!’

Rin looked up and saw Captain Mikoshiba waving at him. The redhead went over. ‘What is it, captain?’

‘I just wanted to discuss your training regimen.’

Rin nodded and let Seijuro do the talking whilst the second year kept an eye on his boyfriend. He was by the starting blocks, wearing his yellow and purple jammers and a stopwatch dangled down from around his neck. Rin had made him leave his windbreaker in the dorm so he couldn’t cover himself up, and a few of the other boys were already staring at Ai’s marks as he warmed up. Rin couldn’t help but smile: everyone was steering clear of his boyfriend.

‘Hey, Nitori!’ Jun shouted as he made his way over to Ai and the smile dropped right off Rin’s face.

Ai looked up, eyes wide. ‘Oh… hi, Hara-senpai.’

‘So, I’ve been thinking about us. And we’ve been skirting around this for ages-’

‘Hara-senpai-’

‘Let me finish. We should take this to the next level. How about you come round to my dorm tonight?’

‘I can’t, Hara-senpai…’

‘Why not? It’s obvious we like each other.’

Rin cleared his throat. ‘Sorry, Captain, but we’ll have to finish this later.’

‘Huh, Matsuoka?’

Rin took off to the starting blocks and grabbed Ai’s wrist.

‘Senpai!’ Ai grinned, thankful for the interruption.

Jun frowned, but before he could ask Ai out again, Rin stepped forwards and pressed his lips to Ai’s, muffling the quiet gasp that came out of his kohai’s mouth. Rin pulled away quickly, not wanting the rest of the swim team to hear Ai whimper and moan and squeak: that was for Rin’s ears only.

‘Did you finish warming up?’ Rin asked.

Ai nodded and Rin took the stopwatch from around his boyfriend’s neck. ‘I’ll time you.’

Ai kissed Rin on the cheek in thanks, then stepped onto the starting block and dived in. Rin started the stopwatch, then turned to Jun, who had flushed red in embarrassment.

‘Rin-kiun, I…’

Rin stepped closer to Jun, his red eyes narrowed in a glare. ‘Stay away from Ai. Am I clear?’

‘Yes, Rin-kun.’ Jun bowed and scuttled away.

Rin smirked and turned to watch his boyfriend swim as fast as he could. Maybe they should do some extra training tonight. Some hands-on training.

**Author's Note:**

> http://lilacchocolate.tumblr.com/


End file.
